Lithium-ion batteries as advanced secondary batteries with great potential play a very important role in portable energy storage devices, electric vehicles (EVs) and hybrid electric vehicles (HEVs) owing to their advantages, such as high energy density, high voltage and environmental benign. Usually, the key to the development of high-performance rechargeable lithium-ion batteries is cathode material. However, conventional cathode materials, such as LiCoO2, LiFePO4, LiNiO2, LiMnO2 and LiMO2 (M is two or more of Ni, Mn and Co), have a low electrochemical capacity with an actual capacity lower than 200 mAh g−1 in general, this has limited their applications in next-generation high-energy-density lithium-ion batteries. Therefore, it is still a great challenge to develop a cahode material with high energy density. Lithium-rich layered material xLi2MnO3.(1−x)LiNi1/2Mn1/2O2 has attracted extensive attentions due to its high capacity (>250 mAh g−1) and low cost, and it is a promising cathode material. The most attractive feature of such lithium-rich layered cathode material is that it can be recharged to a high voltage (>4.5V) through activation of Li2MnO3 component, thereby obtaining a high charge/discharge capacity (>250 mAh g−1) and overcoming the defects of conventional cathode materials, which are unstable at this voltage. Although this kind of layered material has many advantages, they have inherent disadvantages, that is intrinsic poor rate capability and poor cycle stability and etc. It is mainly caused by surface restruction of the material resulting from activation of Li2MnO3 component when the material is charged to above 4.5V, as well as erosion of electrode material by electrolyte, structural changes in the cycling process and other factors.